[1] [1] Yang Z, Li C, Xu S, et al. SingleFrequency Fiber Lasers [M]Optical Fiber Communications Repts (OFCR, volume 8). Singape: Springer Nature Singape Pte Ltd., 2019.

[2] Fu S, Shi W, Feng Y, et al. Review of recent progress on single-frequency fiber lasers[J]. Journal of Optical Society of America B, 34, A49-A62(2017).

[3] Yang C, Cen X, Xu S, et al. Research progress of single-frequency fiber laser[J]. Acta Optica Sinica, 41, 0114002(2021).

[4] Ma P, Chang H, Ma Y, et al. 7.1 kW coherent beam combining system based on a seven-channel fiber amplifier array[J]. Optics & Laser Technology, 140, 107016(2021).

[5] Bode N, Meylahn F, Willke B. Sequential high power laser amplifiers for gravitational wave detection[J]. Optics Express, 28, 29469-29478(2020).

[6] Vercesi V, Onori D, Laghezza F, et al. Frequency-agile dual-frequency lidar for integrated coherent radar-lidar architectures[J]. Optics Letters, 40, 1358-1361(2015).

[7] Ma Y, Wang X, Leng J, et al. Coherent beam combination of 1.08 kW fiber amplifier array using single frequency dithering technique[J]. Optics Letters, 36, 951-953(2011).

[8] Castelvecchi Davide. Gravitational-wave observatory LIGO set to double its detecting power[J]. Nature, 566, 305(2019).

[9] Li Z, Duan H, Huang X, et al. Design and performance test of the spaceborne laser in the TianQin-1 mission[J]. Optics & Laser Technology, 141, 107155(2021).

[10] Wang J, Hou Y, Zhang Q, et al. High-power, high signal-to-noise ratio single-frequency 1 µm Brillouin all-fiber laser[J]. Optics Express, 23, 28978-28984(2015).

[11] Chen M, Meng Z, Wang J, et al. Strong linewidth reduction by compact Brillouin/erbium fiber laser[J]. IEEE Photonics Journal, 6, 1-8(2014).

[12] Shi C, Sheng Q, Fu S, et al. Power scaling and spectral linewidth suppression of hybrid Brillouin/thulium fiber laser[J]. Optics Express, 28, 2948-2955(2020).

[13] Gu J, Yang Y, Liu M, et al. A switchable and stable single-longitudinal-mode, dual-wavelength erbium-doped fiber laser assisted by Rayleigh backscattering in tapered fiber[J]. Journal of Applied Physics, 118, 103107(2015).

[14] Zhu T, Zhang B, Shi L, et al. Tunable dual-wavelength fiber laser with ultra-narrow linewidth based on Rayleigh backscattering[J]. Optics Express, 24, 1324(2016).

[15] Shawki H, Kotb H, Khalil A. Single-longitudinal-mode broadband tunable random laser[J]. Optics Letters, 42, 3247(2017).

[16] Wang Q, Song H, Wang X, et al. Experiments and analysis of tunable monolithic 1-m single-frequency fiber lasers with loop mirror filters[J]. Optics Communications, 410, 884(2018).

[17] Wang K, Lu B, Qi X, et al. Wavelength-tunable single-frequency ytterbium-doped fiber laser based on a double-circulator interferometer[J]. Laser Physics Letters, 16, 015104(2019).

[18] Yin T, Song Y, Jiang X, et al. 400 mW narrow linewidth single-frequency fiber ring cavity laser in 2 μm waveband[J]. Optics Express, 27, 15794(2019).

[19] Lim S, Yoo J, Kim S. Widely tunable watt-level single-frequency Tm-doped fiber ring laser as pump for Mid-IR frequency generation[J]. IEEE Photonics Journal, 8, 1502006(2016).

[20] Wang K, Wen Z, Chen H, et al. Single-frequency all-polarization-maintaining ytterbium-doped bidirectional fiber laser[J]. Optics Letters, 46, 404(2021).

[21] Yin B, Feng S, Liu Z, et al. Tunable and switchable dual-wavelength single polarization narrow linewidth SLM erbium-doped fiber laser based on a PM-CMFBG filter[J]. Optics Express, 22, 22528(2014).

[22] Yin B, Liu Z, Feng S, et al. Stable single-polarization single-longitudinal-mode linear cavity erbium-doped fiber laser based on structured chirped fiber Bragg grating[J]. Applied Optics, 54, 6(2015).

[23] Yan F, Peng W, Liu S, et al. Dual-wavelength single-longitudinal-mode Tm-doped fiber laser using PM-CMFBG[J]. IEEE Photonics Technology Letters, 27, 951(2015).

[24] Wen Q, Sun Z, Gan Y, et al. Sub-kilohertz linewidth fiber laser by using Bragg grating filters[J]. Applied Optics, 60, 4299(2021).

[25] Lu B, Yuan L, Qi X, et al. MoS₂ saturable absorber for single frequency oscillation of highly Yb-doped fiber laser[J]. Chinese Optics Letters, 14, 071404(2016).

[26] Liu X, Ji L, Zhu F, et al. Linear-cavity-based single frequency fiber laser with a loop mirror and Ti₂CT_x quantum dots[J]. Optical Materials, 122, 111686(2021).

[27] Wei Z, Chen S, Ding J, et al. Recent advance in tunable single-frequency fiber laser based on two-dimensional materials[J]. Frontiers of Physics, 8, 580602(2021).

[28] Fu P, Feng X, Lu B, et al. Switchable dual-wavelength SLM narrow linewidth fiber laser based on nonlinear amplifying loop mirror[J]. Optics & Laser Technology, 98, 56(2018).

[29] Xu S, Yang Z, Zhang W, et al. 400 mW ultrashort cavity low-noise single-frequency Yb³⁺-doped phosphate fiber laser[J]. Optics Letters, 36, 3708(2011).

[30] Hofmann P, Voigtlander C, Nolte S, et al. 550-mW output power from a narrow linewidth all-phosphate fiber laser[J]. Journal of Lightwave Technology, 31, 756(2013).

[31] Guan X, Yang C, Qiao T, et al. High-efficiency sub-watt in-band-pumped single-frequency DBR Tm³⁺-doped germanate fiber laser at 1950 nm[J]. Optics Express, 26, 6817(2018).

[32] Fu S, Zhu X, Zong J, et al. Diode-pumped 1.15 W linearly polarized single-frequency Yb³⁺-doped phosphate fiber laser[J]. Optics Express, 29, 30637(2021).

[33] Zhang L, Zhang J, Sheng Q, et al. Watt-level 1.7-μm single-frequency thulium-doped fiber oscillator[J]. Optics Express, 29, 27048(2021).

[34] Zhang J, Sheng Q, Zhang L, et al. 2.56 W single-frequency all-fiber oscillator at 1720 nm[J]. Advanced Photonics Research, 3, 2100256(2022).

[35] Robin C, Dajani I, Pulford B. Modal instability-suppressing, single-frequency photonic crystal fiber amplifier with 811 W output power[J]. Optics Letters, 39, 666(2014).

[36] Huang L, Wu H, Li R, et al. 414 W near-diffraction-limited all-fiberized single-frequency polarization-maintained fiber amplifier[J]. Optics Letters, 41, 1(2017).

[37] Lai W, Ma P, Liu W, et al. 550 W single frequency fiber amplifiers emitting at 1030 nm based on a tapered Yb-doped fiber[J]. Optics Express, 28, 20908(2020).

[38] An Y, Pan Z, Yang H, et al. 400-W single-mode single-frequency laser output from homemade tapered fiber[J]. Acta Physica Sinica, 70, 204024(2021).

[39] Shi C, Fu S, Deng X, et al. 435 W single-frequency all-fiber amplifier at 1064 nm based on cascaded hybrid active fibers[J]. Optics Communications, 502, 127428(2022).

[40] Xue M, Gao C, Niu L, et al. A 51.3 W, sub-kHz-linewidth linearly polarized all-fiber laser at 1560 nm[J]. Laser Physics, 30, 035104(2020).

[41] Guan X, Zhao Q, Lin W, et al. High-efficiency and high-power single-frequency fiber laser at 1.6 μm based on cascaded energy-transfer pumping[J]. Photonics Research, 8, 414(2020).

[42] Wang X, Jin X, Wu W, et al. 310-W single frequency Tm-doped all-Fiber MOPA[J]. IEEE Photonics Technology Letters, 27, 677(2015).

[43] Guan X, Yang C, Gu Q, et al. 316 W high-brightness narrow-linewidth linearly-polarized all-fiber single frequency-laser at 1950 nm[J]. Applied Physics Express, 14, 112004(2021).

[44] Yang C, Zhao Q, Feng Z, et al. 1120 nm kHz-linewidth single-polarization single-frequency Yb-doped phosphate fiber laser[J]. Optics Express, 24, 29794(2016).

[45] Honzatko P, Baravets Y, Myakalwar A. Single-frequency fiber laser based on a fiber ring resonator filter tunable in a broad range from 1023 nm to 1107 nm[J]. Optics Letters, 43, 1339(2018).

[46] Tao Y, Zhang S, Jiang M, et al. High power and high efficiency single-frequency 1030 nm DFB fiber laser[J]. Optics & Laser Technology, 145, 107519(2022).

[47] Tao Y, Jiang M, Li C, et al. Low threshold 1150 nm single-polarization single-frequency Yb-doped DFB fiber laser[J]. Optics Letters, 46, 3705(2021).

[48] Huang L, Yang C, Tan T, et al. Sub-kHz-linewidth wavelength-tunable single-frequency ring-cavity fiber laser for C- and L-band operation[J]. Journal of Lightwave Technology, 39, 4794(2021).

[49] Walasik W, Traoré D, Amavigan A, et al. 2-μm narrow linewidth all-fiber DFB fiber Bragg grating lasers for Ho-and Tm-doped fiber-amplifier applications[J]. Journal of Lightwave Technology, 39, 5096(2021).

[50] Cen X, Guan X, Yang C, et al. Short-wavelength, in-band-pumped single-frequency DBR Tm³⁺-doped germanate fiber laser at 1.7 μm[J]. IEEE Photonics Technology Letters, 33, 350(2021).

[51] Mollaee M, Zhu X, Zong J, et al. Single-frequency blue laser fiber amplifier[J]. Optics Letters, 43, 423(2018).

[52] Fang Q, Xu Y, Fu S, et al. Single-frequency distributed Bragg reflector Nd doped silica fiber laser at 930 nm[J]. Optics Letters, 41, 1829(2016).

[53] Fu S, Zhu X, Zong J, et al. Single-frequency Nd³⁺-doped phosphate fiber laser at 915 nm[J]. Journal of Lightwave Technology, 39, 1808(2021).

[54] Zhu X, Zong J, Miller A, et al. Single-frequency Ho³⁺-doped ZBLAN fiber laser at 1200 nm[J]. Optics Letters, 37, 4185(2012).

[55] Bernier M, Michaud-Belleau V, Levasseur S, et al. All-fiber DFB laser operating at 2.8 μm[J]. Optics Letters, 40, 81(2015).

[56] Hudson D, Williams J, Withford J, et al. Single-frequency fiber laser operating at 2.9 μm[J]. Optics Letters, 38, 2388(2013).

[57] Loranger S, Karpov V, Schinn G, et al. Single-frequency low-threshold linearly polarized DFB Raman fiber lasers[J]. Optics Letters, 42, 3864(2017).

[58] Wu J, Zhu X, Wei H, et al. Power scalable 10 W 976 nm single-frequency linearly polarized laser source[J]. Optics Letters, 43, 951(2018).

[59] Gouhier B, Guiraud G, Rota-Rodrigo S, et al. 25 W single-frequency, low noise fiber MOPA at 1120 nm[J]. Optics Letters, 43, 308(2018).

[60] Gouhier B, Dixneuf C, Hilico A, et al. Low Intensity noise high-power tunable fiber-based laser around 1007 nm[J]. Journal of Lightwave Technology, 37, 3539(2019).

[61] Gouhier B, Rota-Rodrigo S, Guiraud G, et al. Low-noise single-frequency 50 W fiber laser operating at 1013 nm[J]. Laser Physics Letters, 16, 045103(2019).

[62] Yao B, Chen Q, Chen Y, et al. 280 mHz linewidth DBR fiber laser based on PDH frequency stabilization with ultrastable cavity[J]. Chinese Journal of Lasers, 48, 0501014(2021).

[63] Zhao Q, Zhang Z, Wu B, et al. Noise-sidebands-free and ultra-low-RIN 1.5 μm single-frequency fiber laser towards coherent optical detection[J]. Photonics Research, 6, 326(2018).

[64] Zhao Q, Zhou K, Wu Z, et al. Near quantum-noise limited and absolute frequency stabilized 1083 nm single-frequency fiber laser[J]. Optics Letters, 43, 42(2018).

[65] Qi Z, Yin T, Jiang X, et al. Narrow-linewidth high-efficiency single-frequency ytterbium-doped fiber laser with highly linear polarization at 1064 nm[J]. Applied Optics, 60, 2833(2021).

[66] Hao L, Wang X, Jia K, et al. Narrow-linewidth single-polarization fiber laser using non-polarization optics[J]. Optics Letters, 46, 3769(2021).

[67] Liu H, Lu Q, Wei S, et al. Long-term stable 850-Hz linewidth single-longitudinal-mode ring cavity fiber laser using polari-zation-maintaining fiber[J]. Applied Physics B, 126, 106(2020).

[68] Yang C, Xu S, Chen D, et al. 52 W kHz-linewidth low-noise linearly-polarized all-fiber single-frequency MOPA laser[J]. Journal of Optics, 18, 055801(2016).

[69] Wellmann F, Steinke M, Meylahn F, et al. High power, single-frequency, monolithic fiber amplifier for the next generation of gravitational wave detectors[J]. Optics Express, 27, 28523(2019).

[70] Dixneuf C, Guiraud G, Bardin Y, et al. Ultra-low intensity noise, all fiber 365 W linearly polarized single frequency laser at 1064 nm[J]. Optics Express, 28, 10960(2020).

[71] Darwich D, Bardin Y, Goeppner M, et al. Ultralow-intensity noise, 10 W all-fiber single-frequency tunable laser system around 1550 nm[J]. Applied Optics, 60, 8550(2021).

[72] Zhang Q, Hou Y, Wang X, et al. 5 W ultra-low-noise 2 µm single-frequency fiber laser for next-generation gravitational wave detectors[J]. Optics Letters, 45, 4911(2020).

[73] Hou Y, Zhang Q, Qi S, et al. 1.5 μm polarization-maintaining dual-wavelength single-frequency distributed Bragg reflection fiber laser with 28 GHz stable frequency difference[J]. Optics Letters, 43, 1383(2018).

[74] Budarnykh A, Vladimirskaya A, Lobach I, et al. Broad-range self-sweeping single-frequency linearly polarized Tm-doped fiber laser[J]. Optics Letters, 43, 5307(2018).

[75] Kashirina E, Lobach I, and Kablukov S. Single-frequency self-sweeping Nd-doped fiber laser[J]. Optics Letters, 44, 2252(2019).

[76] Li K, Deng H, Yang C, et al. Multi-wavelength, passively Q-switched, single-frequency fiber laser[J]. IEEE Photonics Technology Letters, 31, 1479(2019).

[77] Huang L, Guan Z, Yang C, et al. High-precision tunable single-frequency fiber laser at 1.5 μm based on self-injection locking[J]. IEEE Photonics Technology Letters, 34, 633-636(2021).

[78] Bai Z, Jin D, Ding J, . Brillouin laser power exceeds 20 W[J]. Chinese Journal of Lasers, 48, 2116003(2021).

[79] Guo Y, Xu M, Peng W, et al. Realization of a 101 W single-frequency continuous wave all-solid-state 1064 nm laser by means of mode self-reproduction[J]. Optics Letters, 43, 6017(2018).

[80] Peng W, Jin P, Li F, et al. A review of the high-power all-solid-state single-frequency continuous-wave laser[J]. Micro-machines, 12, 1426(2021).

[81] Schülzgen A, Li L, Temyanko V, et al. Single-frequency fiber oscillator with watt-level output power using photonic crystal phosphate glass fiber[J]. Optics Express, 14, 7087(2006).

[82] Tao Y, Jiang M, Liu L, et al. Single-polarization single-frequency Brillouin fiber laser emits near 5-W power at 1 μm[J]. Optics Letters, 47, 1742(2022).

[83] Goodno G, Book L, Rothenberg J. Low-phase-noise, single-frequency, single-mode 608   W thulium fiber amplifier[J]. Optics Letters, 34, 1204(2009).

[84] Huang L, Lai W, Ma P, et al. Tapered Yb-doped fiber enabled monolithic high-power linearly polarized single-frequency laser[J]. Optics Letters, 45, 4001(2020).

[85] Otto H, Jauregui C, Stutzki F, et al. Controlling mode instabilities by dynamic mode excitation with an acousto-optic deflector[J]. Optics Express, 21, 17285(2013).

[86] Jauregui C, Stihler C, Tünnermann A, et al. Pump-modulation-induced beam stabilization in high-power fiber laser systems above the mode instability threshold[J]. Optics Express, 26, 10691(2018).

[87] Stihler C, Jauregui C, Kholaif S, et al. Intensity noise as a driver for transverse mode instability in fiber amplifiers[J]. PhotoniX, 1, 8(2020).

[88] Sincore A, Bradford J, Cook J, et al. High average power thulium-doped silica fiber lasers: Review of systems and concepts[J]. Journal of Selected Topics in Quantum Electronics, 24, 0901808(2017).

[89] Creeden D, Johnson B, Setzler S, et al. Resonantly pumped Tm-doped fiber laser with >90% slope efficiency[J]. Optics Letters, 39, 470(2014).

[90] Wang Y, Yang J, Huang C, et al. High power tandem-pumped thulium-doped fiber laser[J]. Optics Express, 23, 2991(2015).

[91] Dianov E. Bismuth-doped optical fibers: A challenging active medium for near-IR lasers and optical amplifiers[J]. Light-Science & Applications, 1, e12(2012).

[92] Thipparapu N, Wang Y, Umnikov A, et al. Bi-doped fiber amplifiers and lasers [Invited][J]. Optical Materials Express, 9, 2446(2019).

[93] Zhang L, Jiang H, Cui S, et al. Versatile Raman fiber laser for sodium laser guide star[J]. Laser & Photonics Reviews, 8, 889(2014).

[94] Miao Y, Ma P, Liu W, et al. First demonstration of co-pumped single-frequency Raman fiber amplifier with spectral-broadening-free property enabled by ultra-low noise pumping[J]. IEEE Access, 6, 71988(2019).

[95] Xu Y, Mak K, and Murdoch S. Multiwatt level output powers from a tunable fiber optical parametric oscillator[J]. Optics Letters, 36, 1966(2011).

[96] Yang S, Cheung K, Zhou Y, et al. Tunable single-longitudinal-mode fiber optical parametric oscillator[J]. Optics Letters, 35, 481(2010).

[97] Lim L, Abu Bakar M, and Mahdi M. Wavelength-tunable single longitudinal mode fiber optical parametric oscillator[J]. Optics Express, 25, 5501(2017).

[98] Zou J, Li T, Dou Y, et al. Direct generation of watt-level yellow Dy³⁺-doped fiber laser[J]. Photonics Research, 9, 446(2021).

[99] Lord M, Fortin V, Maes F, et al. 2.3 W monolithic fiber laser operating in the visible[J]. Optics Letters, 46, 2392(2021).

[100] Fortin V, Jobin F, Larose M, et al. 10-W-level monolithic dysprosium-doped fiber laser at 3.24 μm[J]. Optics Letters, 44, 491(2019).

[101] Lemieux-Tanguay M, Fortin V, Boilard T, et al. 15 W monolithic fiber laser at 3.55 µm[J]. Optics Letters, 47, 289(2022).

[102] Häfner S, Falke S, Grebing C, et al. 8 × 10⁻¹⁷ fractional laser frequency instability with a long room-temperature cavity[J]. Optics Letters, 40, 2112(2015).

[103] [103] Dahl K, Cebeci P, Fitzau O, et al. A new laser technology f LISA [C]International Conference on Space Optics, 2018: 111800 C.

[104] Vahlbruch H, Wilken D, Mehmet M, et al. Laser power stabilization beyond the shot noise limit using squeezed light[J]. Physical Review Letters, 121, 173601(2018).

[105] Wang Y, Gao L, Zhang X, et al. Recent development of low noise laser for precision measurement (Invited)[J]. Infrared and Laser Engineering, 49, 20201073(2020).

[106] Popp A, Distler V, Jaksch K, et al. Quantum-limited measurements of intensity noise levels in Yb doped fiber amplifiers[J]. Applied Physics B, 126, 130(2020).

[107] Tünnermann H, Neumann J, Kracht D, et al. Gain dynamics and refractive index changes in fiber amplifiers: a frequency domain approach[J]. Optics Express, 20, 13539(2012).

[108] Tünnermann H, Neumann J, Kracht D, et al. Frequency resolved analysis of thermally induced refractive index changes in fiber amplifiers[J]. Optics Letters, 37, 3597(2012).

[109] Zhao J, Guiraud G, Floissat F, et al. Gain dynamics of clad-pumped Yb-fiber amplifier and intensity noise control[J]. Optics Express, 25, 357(2017).

[110] Gierschke P, Jauregui C, Gottschall T, et al. Relative amplitude noise transfer function of an Yb³⁺-doped fiber amplifier chain[J]. Optics Express, 27, 17041(2019).

[111] Zhao N, Li W, Li J, et al. Elimination of the photodarkening effect in an Yb-doped fiber laser with deuterium[J]. Journal of Lightwave Technology, 37, 3021(2019).

[112] Zhao N, Peng K, Li J, et al. Photodarkening effect suppression in Yb-doped fiber through the nanoporous glass phase-separation fabrication method[J]. Optical Materials Express, 9, 1085(2019).

[113] Theeg T, Ottenhues C, Sayinc H, et al. Core-pumped single-frequency fiber amplifier with an output power of 158 W[J]. Optics Letters, 41, 9(2016).

[114] Zhao J, Guiraud G, Pierre C, et al. High-power all-fiber ultra-low noise laser[J]. Applied Physics B, 124, 114(2018).

[115] Wei L, Cleva F, Nary Man C. Coherently combined master oscillator fiber power amplifiers for Advanced Virgo[J]. Optics Letters, 41, 5817(2016).

[116] Wellmann F, Bode N, Wessels P, et al. Low noise 400 W coherently combined single frequency laser beam for next generation gravitational wave detectors[J]. Optics Letters, 29, 10140(2021).

[117] Ball G, Morey W, Glenn W. Standing-wave monomode erbium fiber laser[J]. IEEE Photonics Technology Letters, 3, 613(1991).